Perhaps the most revolutionary technological development in recent years has been the personal computer. While the earliest computers date back many years, the personal computer as we know it today originated in the mid-1970's. By most standards, then, the history of the personal computer has been relatively short. The first personal computers were the "brain children" of small entrepreneurial companies, some of which are no longer in existence. While some would dispute who actually deserves credit for developing the first personal computer, it is these small enterprises which have become the precursors of virtually all personal computers available on the market today.
While the capacity of these early machines is minuscule by today's standards, these machines revolutionized the home and office personal computer industry. The performance capabilities of personal computers today are quite astonishing. The processor speed and memory capacity of today's generation of work horse computers far exceed those of previous generations and are increasing exponentially as technology rapidly develops. The vast majority of personal computers operate in a Windows.RTM. environment, which to many is a more user-friendly working environment. While MS-DOS is slowly dying a lingering death, with the expectation that it will eventually be superseded entirely, there are those who refuse to accept the transition due to a psychological dependence upon existing MS-DOS operations.
A virtual necessity of Windows-based operating systems is a pointing device which is employed to activate a cursor across the computer's display screen. The pointing device is typically in the form of either a mouse, a track ball, or a joystick. A mouse is a controller that is moved over a flat surface. As it moves, electrical pulses inform the computer of its exact change in position. The computer responds to this information by shifting a cursor across the display screen in a direction corresponding to motion of the mouse. By pointing the cursor on the screen to a selected icon and then "clicking" a switch on the mouse, the command represented by the selected icon is executed. Internal to the mouse device is a track ball that transmits rotary motion to two slotted disks which each contain a pair of light-emitting diodes and a pair of photodiodes. As the track ball rotates, light shines through slots on the disk and produces electric signals to the photodiodes, which signals correspond to changes in the mouse's coordinates. As the mouse moves, horizontal and vertical coordinates of the cursor change, thereby giving it a new position on the display screen. By verifying these coordinates, the computer learns the location of the cursor and can identify different icons in sections on the display screen. A track ball functions similarly to a mouse and may be employed as either a separate plug-and-play device, or contained within the computer's console.
Another type of pointing device, and one in which the present invention is particularly concerned, is generically referred to as a mini-joystick. Two types of mini-joysticks are currently available, one which incorporates strain gauge technology and one which incorporates force sensing resistor technology (FSR). With both of these types of devices, manipulation of the mini-joystick in a desired direction causes the cursor to travel across the computer's display screen in a corresponding direction. Where portable computers are particularly concerned, the mini-joystick has become quite popular in recent years. Mini-joystick modules are dual click-button pointing devices designed for integration into tight, cramped spaces within the computer's housing. Their slim profile requires less than 0.25" of mounting depth, much less than typical track balls or joysticks. On laptop computers, mini-joysticks are located between keys on the keyboard and are fingertip activated to deliver simultaneous 360.degree. control of cursor direction and speed. Typically, a working region of the computer which is located adjacent to the keyboard includes a pair of depressible mouse buttons to provide additional cursor control in the Windows.RTM. environment.
The pointing devices discussed above, among others, are widely employed by computer users today. Despite the popularity of these devices, however, they do have their drawbacks. One drawback common to each of these pointing devices is that a user has to continually reposition his/her hands in order to effectively and efficiently operate the pointing device. As such, the user cannot maintain his/her hands in the conventional typing position on the keyboard during use of the pointing device. While this drawback is more evident with external pointing devices, such as the mouse discussed above, it is also quite pronounced with integrated pointing devices.
Accordingly, a need exists to provide a new and improved cursor control device which does not require fingertip manipulation during use. It would also be advantageous to provide such a new and improved cursor control device which allows a user to maintain his/her fingers in the conventional typing position on a keyboard during operation. The present invention is particularly directed to meeting these needs among others.